Heretofore, in a control device for a vehicle capable of automatic stop/automatic restart, a technology in which a main battery electrically connected to a starter, a sub battery electrically connected to an electric load of the vehicle, and a relay capable of switching whether the main battery and the sub battery are to be electrically connected or not by turning on/off the relay are provided and the starter is operated by turning off the relay at the time of restart after automatic stop of an engine (see JP2008-82275A). As a result, at the time of operating the starter, it is possible to prevent a voltage drop (instantaneous voltage drop) of the sub battery from occurring, and this makes it possible to prevent power supply shortage to the electric load. Further, it is also possible to charge the main battery and the sub battery by means of an alternator driven by the engine by turning on the relay.